Engineering the Photocatalytic Behaviors of g/C3N4-Based Metal-Free Materials for Degradation of a Representative Antibiotic

Abstract

Graphitic carbon nitride (g/C₃N₄) is of promise as a highly efficient metal-free photocatalyst, yet engineering the photocatalytic behaviours for efficiently and selectively degrading complicated molecules is still challenging. Herein, the photocatalytic behaviors of g/C₃N₄ are modified by tuning the energy band, optimizing the charge extraction, and decorating the cocatalyst. The combination shows a synergistic effect for boosting the photocatalytic degradation of a representative antibiotic, lincomycin, both in the degradation rate and the degree of decomposition. In comparison with the intrinsic g/C₃N₄, the structurally optimized photocatalyst shows a tenfold enhancement in degradation rate. Interestingly, various methods and experiments demonstrate the specific catalytic mechanisms for the multiple systems of g/C₃N₄-based photocatalysts. In the degradation, the active species, including ·O₂⁻, ·OH, and h⁺, have different contributions in the different photocatalysts. The intermediate, H₂O₂, plays an important role in the photocatalytic process, and the detailed functions and originations are clarified for the first time.